This is a multicenter chemoprevention seven year clinical trial using finasteride to reduce the incidence of prostate cancer in healthy men. Finasteride is a 5-alpha-reductase inhibitor which may play a pivotal role in the initialization and progression of prostate cancer. After an initial run-in period, volunteers without evidence of prostate enlargement and with a normal PSA will be randomized to receive either daily finasteride or matched placebo for 7 years or until development of prostate-related symptoms. Progress report and summary of findings: This prostate cancer prevention trial is a double blind placebo, controlled trial, which remains ongoing. As such, there are no results on outcome to report at this point in time. No adverse experiences have been encountered at NYH- CUMC.